of nanowire superlattices with new photonic and electronic properties, the basis of intensive efforts today in nanowire photonics and electronics. Nanostructure characterization. Lieber developed applications of scanning probe microscopies that could provide direct experimental measurement of the electrical and mechanical properties of individual carbon nanotubes and nanowires. This work showed that semiconductor nanowires with controlled electrical properties can be synthesized, providing electronically tunable functional nanoscale building blocks for device assembly. Additionally, Lieber invented chemical force microscopy to characterize the chemical properties of materials surfaces with nanometer resolution. Nanoelectronics and nanophotonics. Lieber has used quantum-confined core/shell nanowire heterostructures to demonstrate ballistic transport, the superconducting proximity effect, and quantum transport. Other examples of functional nanoscale electronic and optoelectronic devices include nanoscale electrically driven lasers using single nanowires as active nanoscale cavities, carbon nanotube nanotweezers, nanotube-based ultrahigh-density electromechanical memory, an all-inorganic fully integrated nanoscale photovoltaic cell and functional logic devices and simple computational circuits using assembled semiconductor nanowires. These concepts led to the integration of nanowires on the Intel roadmap, and their current top-down implementation of these structures. Nanostructure assembly and computing. Lieber has originated a number of approaches for parallel and scalable of assembly of nanowire and nanotube building blocks. The development of fluidic-directed assembly and subsequent large-scale assembly of electrically addressable parallel and crossed nanowire arrays was cited as one of the Breakthroughs of 2001 by Science. He also developed a lithography-free approach to bridging the macro-to-nano scale gap using modulation-doped semiconductor nanowires. Lieber recently introduced the assembly concept "nanocombing", to create a programmable nanowire logic tile and the first stand-alone nanocomputer. Nanoelectronics for biology and medicine. Lieber demonstrated the first direct electrical detection of proteins, selective electrical sensing of individual viruses and multiplexed detection of cancer marker proteins and tumor enzyme activity. More recently, Lieber demonstrated a general approach to overcome the Debye screening that makes these measurements challenging in physiological conditions, overcoming the limitations of sensing with silicon nanowire field-effect devices and opening the way to their use in diagnostic healthcare applications. Lieber has also developed nanoelectronic devices for cell/tissue electrophysiology, showing that electrical activity and action potential propagation can be recorded from cultured cardiac cells with high resolution. Most recently, Lieber realized 3D nanoscale transistors in which the active transistor is separated from the connections to the outside world. His nanotechnology-enabled 3D cellular probes have shown point-like resolution in detection of single-molecules, intracellular function and even photons. Nanoelectronics